Certain kinds of alkoxyimino compounds have been noted because they are known to have excellent fungicidal activities against microorganisms such as Pyricularia oryzae, Rhizoctonia solani, Pseudoperonospora cubensis and the like. Some of the compounds and their production have been known (JP-A 63-23852 and JP-A 63-30463).
The present inventors have already filed patent applications (JP-A 3-246268, JP-A 4-89464 and JP-A 4-182461, etc.) on the alkoxyiminoacetamide compound represented by the general formula (V): ##STR2## wherein A is a hydrogen atom, a halogen atom, alkyl, alkenyl, alkynyl, alkoxy, alkyl halide, alkenyl halide, alkynyl halide, cycloalkyl, cycloalkenyl, optionally substituted phenyl or optionally substituted heterocyclic group, Z is --CH.sub.2 --, --O--, --S--, --CH(OH)--, --CO--, --NR-- (wherein R is a hydrogen atom or alkyl), --CH.sub.2 CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C--, --CH.sub.2 O--, --CH.sub.2 S--, --CH.sub.2 S(O)--, --OCH.sub.2 --, --SCH.sub.2 --, --S(O)CH.sub.2 -- or epoxy, R.sup.2 and R.sup.3 are the same or different and are a hydrogen atom, alkyl or cycloalkyl, R.sup.4 is alkyl or cycloalkyl, .about.indicates any configuration of the E isomer, Z isomer and the mixture thereof, and processes for producing it.
In these processes, the .alpha.-ketoamide of the general formula (III): ##STR3## wherein each symbol is as defined above, is important as a common intermediate for the production of various alkoxyiminoacetamide compounds (V). For example, EP-A 398692 discloses a process for producing the .alpha.-ketoamide shown in the following scheme: ##STR4## wherein R.sup.a is, for example, lower alkyl, R.sup.b, R.sup.c and R.sup.d are the same meaning as R.sup.2, R.sup.3 and R.sup.4, respectively.
However, this process employs as the starting material an .alpha.-ketocarboxylic acid ester which can be prepared with difficulty. Therefore, an improved production process thereof has been required by which not only the compound (III) but also its starting material can be produced economically and efficiently.